As fuel prices go up, is the Innova Crysta's fuel efficiency a cause for worry?

This was the Toyota Innova Crysta, widely popular in its diesel variant, thanks to an immense load carrying ability and utterly strong performance. Still, the vehicle’s fuel efficiency is being called into question, as fuel prices continue to rise in India. As a large and taxing vehicle the Innova Crysta obviously consumes more fuel than smaller cars and even some SUVs. This leads to questions about its long term running cost, a question especially for individual owners and fleet operators. Sometimes the vehicle offers reliability and low maintenance costs which are put forward as counterweights but never can fuel costs be discounted. This brings up the discussion of (what should be) the balance of performance and efficiency. Would you pay more for fuel to have the power and comfort of the Innova? Anyways, how does that compare to more fuel efficient alternatives in terms of total ownership costs? How do the petrol and diesel variants do when you drive them in the real world? On low speed urban use, does it improve significantly with respect to city use?